Drug delivery devices are generally known for the administration of a medicinal product, for example insulin or heparin, but also for other medicinal products for self-administration by a patient. Most of the drug delivery devices are pen-type injectors, which dispense a pre-set dose of a fluid medicinal product.
Document EP 0 058 536 A1 shows an example for a drug delivery device where a pre-set dose can be administered. For dispensing the dose, a plunger is screwed with respect to a fixed sleeve, thereby advancing a plug in a fluid containing cylinder.
Before the first use of the drug delivery device the user usually has to prime the drug delivery device. Users who are unfamiliar with such pen-type injectors may fail or incorrectly prime their drug delivery device before dispensing the first dose.